Meter Widget

 
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METER Widget
Graphically displays a numeric value with a needle that sweeps along an arc
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Legal Usage                Level-0 Widget:                Yes
                 Parent to:                None
                 Child of:                        PANEL
 
Example Image
 
     
 
Example Program
 
See METER Widget for a program that creates a METER widget with a display similar to that shown above, except that the needle sweep is 360 degrees.
 
NOTE
 
See the following programs for other examples using the METER widget:
 
         Bar Meter Limits
         Engine Monitor - Level-0
         Engine Monitor - Panel
         Environmental Chamber
         METER/SLIDER Widgets
         Oven Control
         PID Controller
 
Attributes
 
See METER Widget Attributes for the METER widget attribute list.
 
Remarks
 
The METER widget graphically displays a numeric value with a needle that sweeps along an arc.The METER widget programming operation is virtually identical to BAR widget programming. The METER widget displays its MINIMUM limit, MAXIMUM limit, and CURRENT VALUE in boxes. You can set the SWEEP ANGLE to 360 degrees to give this widget a tachometer-like appearance.
 
An event can be generated on any or all of the three ranges: "LOW", "MIDDLE", or "HIGH". METER widget events are level-triggered, not edge-triggered. An event is generated any time a VALUE is within the designated ALARM RANGE, not only when the VALUE transitions from one range to the other. You must specifically set the ALARM TYPE to event before an event can be generated. Otherwise, only beeps are generated.
 
Events
 
Events for the METER widget are:
 
·
ALARM
·
SYSTEM MENU
 
ALARM
 
This event is generated when the VALUE attribute is set to a value within one of the ranges named in the ALARM RANGES attribute and ALARM TYPE is EVENT. The only time an ALARM event is generated is when the value of VALUE is set to one of the following:
 
·
To or above HIGH LIMIT and the value of ALARM RANGES is "HIGH"
 
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Between and including LOW LIMIT and HIGH LIMIT and the value of ALARM RANGES is "MIDDLE"
 
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To or below LOW LIMIT and the value of ALARM RANGES is "LOW"
 
Redraw activities, such as changing the ORIENTATION attribute value, will not generate an ALARM event.
 
SYSTEM MENU
 
This event is generated when the operator selects items from the SYSTEM MENU.